Any substance that causes the production of antibodies by the body's immune system. Common antigens include the proteins carried on the surface of bacteria, viruses, and pollen grains. The proteins of incompatible blood groups or tissues also act as antigens, which has to be taken into account in medical procedures such as blood transfusions and organ transplants.
The star represents Islam and expresses peace, harmony, hope, and socialism. The tricolour is reminiscent of the flag of France, the former colonial power. The pan-African colours express unity with other African nations. Effective date: 25 August 1960.